Windows: Description and Operation

POWER WINDOWS DESCRIPTION AND OPERATION

POWER WINDOW SYSTEM COMPONENTS
The power window system consists of the following components:
- LF power window master switch
- RF power window switch
- LR power window switch (4-door vehicles)
- RR power window switch (4-door vehicles)
- Window lockout switch (4-door vehicles)
- Window up and window down relays in each of the passenger window switches
- Reversible power window motors in each of the doors (circuit breaker protected).
- PWR WDO CB 25A (fuse block) (System power for left and right windows 2-door vehicles. System power for LF and LR windows 4-door vehicles)
- PWR WDO CB 25A (IP wiring harness junction block) (System power for RF and RR windows 4-door vehicles)

POWER WINDOW SYSTEM CONTROLS
The power window system will operate anytime the Retained Accessory Power (RAP) system is active or when the ignition switch is in the ACCY or ON position.

The LF power window master switch can control the up and down functions of all the windows in the vehicle. The passenger door power window switches can only control the up and down functions of the individual window. The power window master switch also contains a lockout switch (4 door vehicles). The lockout switch controls the power window master switch lockout signal circuit. When the lockout switch is in the OFF position, the power window master switch lockout signal circuit is complete and the passenger door power window switches function normally. When the lockout switch is in the ON position, the power window master switch lockout signal circuit is interrupted and the passenger door window switches cannot control the up and down functions of the power windows.

POWER WINDOW MOTOR OPERATION
A permanent magnet motor operates each of the power side windows. Each motor raises or lowers the glass when the motor receives voltage. The direction the motor turns depends on the polarity of the supply voltage. The power window switches control the polarity of the supply voltage. A built-in circuit breaker protects each motor. The circuit breaker opens when the switch is depressed for a extended period of time under the following conditions:
- The window has an obstruction.
- The window is fully open or fully closed.

The circuit breaker will reset automatically as the circuit breaker cools.

DRIVER POWER WINDOW OPERATION
The driver power window is unique from the passenger power windows in that it does not use window up and down relays. The driver power window is operated directly from the power window switch.

The normally closed contacts of the switch are connected to ground and the center pole is connected to the RAP fuse supply voltage circuit. By placing the left power window switch in the down position, voltage is applied to the power window motor left front down circuit and to the power window motor. The other side of the power window motor is connected to ground through the normally closed contacts of the left power window switch through the power window motor left front up circuit and drives the window down.

By placing the left power window switch in the up position the polarity of the motor is reversed and the motor drives the window up.

PASSENGER POWER WINDOW OPERATION
The passenger power window switches incorporate window up and down relays. The relay coil feed and supply sides are powered through the RAP fuse supply voltage circuit. The normally closed contacts of each relay is connected to ground. The load side of each of the relays are connected to either side of the power window motor through the power window up and down circuits. The up and down relay control circuits are connected to the normally closed contacts of the passenger window switch. These contacts are wired in series with the power window master switch, through the power window master switch up and down signal circuits and then to ground when the power window master is placed in the up or down position. This allows for the up and down operation of the passenger power window from the power window master switch. The center pole of the passenger power window switch is also connected to ground and will energize the relay when placed in the up or down position.

EXPRESS DOWN OPERATION
Vehicles equipped with the express down function incorporate an auto down module in the power window master switch. The auto down module senses the operation of the LF window switch and controls voltage and ground availability to the power window up and down circuits.

When the LF power window switch is held in the down position for more then 1 second, the auto down module supplies voltage to the power window down circuit continuously until the power window reaches the bottom of its travel. At this point, the auto down module senses an over current situation on the power window down circuit and interrupts the voltage supply. If the LF power window switch is actuated less then 1 second, the operation is the same except the power window down circuit will be interrupted when the switch is released.